1. Field of the Disclosure
This disclosure relates generally to devices, systems, and methods to maintain constant fluid circulation during the drilling of a borehole.
2. Background of the Art
During drilling of boreholes, drilling fluids may be used to stabilize the borehole, cool and lubricate drilling equipment, and to apply a desired pressure to a formation being drilled. During drilling, the drilling fluid is circulated continuously. Conventionally, when a new section of drill pipe is connected to or disconnected from the top of a drill string, the circulation of drilling fluid is stopped. When circulation stops, the drilling fluid may settle and increase in viscosity. Thus, the drilling fluid circulation pumps may have to overcome a pressure increase to re-start circulation. Moreover, some formations may have relatively narrow margins between fracturing gradient and pore pressure. Maintaining pressure on the formation within these margins may be challenging during interruptions in drilling fluid circulation.
The present disclosure addresses the need for providing continuous fluid circulation during interruptions in drilling.